1. Field of the Invention
The present invention relates to a method as well as a corresponding network component, both used in a communications network, for switching connections with a low bit rate between input modules and output modules of the network component.
2. Description of the Prior Art
In communications networks such as mobile radio networks or stationary networks, information--e.g. traffic information or signaling information in speech transmission--is transmitted with low transmission rates via lines between network components by means of TDMA (Time Division Multiplex Access). Thus, PCM30 or PCM24 terminal lines can be employed. For hardwired information transmission--in stationary networks, but also in mobile radio networks, especially of the next generation--ATM (Asynchronous Transfer Mode) transmission, due to its advantages regarding broadband applications, is gaining increasing acceptance. Nevertheless, narrowband information transmission via connections with a low bit rate--e.g. TDM connections--remains an important application for the majority of the mobile or stationary network subscribers. Therefore, when the TDM multiplex technology is converted or translated into ATM transmission technology in a network component, a large delay usually arises--e.g. 8 msec given 8 kbit/sec speech transmission. This leads to a degradation of the speech quality.
In principle, a conversion procedure from TDM multiplex technology into ATM transmission technology does exist which leads only to small delays--e.g. by filling the ATM cells with only a few bytes--however, this results in an uneconomical use of the ATM bandwidth. For this reason, it has long been a problem to realize network components of a telecommunications network so that they distribute the traffic internally via an ATM switching means and simultaneously support TDM traffic with a low bit rate at the external lines.